Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, thin, continuous, quickly becoming rimose-areolate, areoles up to c. 0.5 mm wide, plane surface: dark gray, dull; margin: indeterminate; prothallus: lacking blastidia: arising from areole margins and then areole surface, finally forming an entirely blastidiate thallus, darker than thallus, dark gray-brown, spherical, 40-70 µm in diam., or elongate, 80-90(-120) x 90-120(-230) µm Apothecia: erumpent, becoming adnate to sessile, infrequent in continuously blastidiate parts of thallus, often abundant in non-blastidiate areas, not contiguous, up to 0.4-0.5 mm in diam. disc: persistently plane or becoming slightly convex, dark brown to black thalline margin: concolorous with thallus, 0.05-0.1 mm wide, sometimes blastidiate, persistent, or margin sometimes lacking in part; excipular ring: often prominent, raised thalline exciple: 50-90 µm wide laterally; cortex: 10-15 µm thick; epinecral layer: c. 10 µm thick; cortical cells: up to 4-6 µm wide, not pigmented; algal cells: up to 9.5-10 µm in diam.; thalline exciple: 45-80 µm wide below when apothecia sessile; cortex: 10-20 µm thick, cellular proper exciple: hyaline, 5-10 µm wide laterally, expanding to 30-50 µm at periphery hymenium: 70-100 µm tall; paraphyses: 2-2.5 µm wide, conglutinate, with apices 4.5-6 µm, pigmented light brown to reddish brown, forming a similarly colored epihymenium; hypothecium: hyaline, 40-70 µm thick asci: clavate, 40-60 x 16-19 µm, 8-spored ascospores: brown, 1-septate, broadly ellipsoid, type A development, Pachysporaria-type, (13-)15.5-17.5(-20) x (7-)9-10.5(-13) µm, sometimes slightly waisted at maturity; torus: absent or narrow; walls: not ornamented Pycnidia: immersed; conidiophores: type VI conidia: bacilliform, 3.5-4.5 x c. 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: collected with R. herrei on horizontal branches of Quercus agrifolia in moist habitats World distribution: previously known only from the type locality in Austria and new to North America (Monterey and Santa Barbara Counties, California) Sonoran distribution: Santa Rosa and Santa Cruz Islands. Notes: The Californian collections are very similar to the European type and differ only in possessing larger blastidia, a shallower hypothecium, and less expanded lower apothecial cortex. The only other western North American blastidiate species with Pachysporaria-type spores is R. perreagens. This species is easily distinguished by the presence of pannarin, its less expanded lower apothecial cortex, and by its much larger spores. Another species with vegetative propagules that can be added to the list of western North American species (Sheard 1995) with disjunctions in Europe.